


War of Hearts

by CelesteNox



Category: Overwatch (Video Game)
Genre: Age Difference, F/M, OC/Canon, Original Character(s), Originally Posted on Tumblr, Self-Insert
Language: English
Status: Completed
Published: 2019-07-31
Updated: 2019-07-31
Packaged: 2021-03-05 06:28:42
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,831
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/25289839
Author URL: https://archiveofourown.org/users/CelesteNox/pseuds/CelesteNox
Summary: The title is based on Ruelle's "War of Hearts". I found it via an MEP video.This was my first self-insert x canon fanfic. I wrote it back in 2019 and posted it to my self-ship tumblr. I think only one other person read it, but I don't really care. It's one of my favorite fics I've ever written!While I say this is a one-off, it's technically a part of an overarching series, but I haven't written any other stories yet.I'm new to the site and tagging things properly was a bit of a challenge, so please let me know if I did something wrong.
Relationships: Sigma | Siebren de Kuiper/Original Female Character(s)
Kudos: 1





	War of Hearts

It was strange to think that a man whose thoughts were consumed by the majesty of the universe, a man who devoted his life, his body, his very _soul_ to science and the pursuit of knowledge, could be so dumb-stricken by the mere existence of another person. Yet there he was, his eyes widened and jaw agape at the letter he held in his trembling hands. He’d found the folded paper on his work desk, it’s corner placed under his coffee mug. The letter, typed onto light blue paper, was a confession of love from an intern who had been working under him in the research division for months. She had always treated him with a kindness, a sweetness that the other Talon agents sorely lacked.

Siebren’s periwinkle eyes darted across the page, unblinking, as he read what she had written him:

## “ _Mr. de Kuiper,_

_I’d first like to apologize for not having the courage to tell you this in person. I fear what might come from such a confession, which is why I’ve decided to write this letter and leave it for you to find. Please don’t be angry with me, I just can not hide my feelings for you any longer._

_From that first fateful day, the day we met, I have been absolutely smitten with you. I figured that it was just infatuation, that it would pass as quickly as it came, but 7 months later, I still feel the same. Spending so much time with you, listening to your theories and your self-described “old-man ramblings”, means the world to me. I could listen to you speak for hours, sir, days even! With every breath you take, I fall even deeper into love._

_I’ve caught myself studying you, sir. Paying attention to everything you like, everything you hate, everything you do. For example, after you’ve written a lengthy paper, you always sit down for a cup of coffee (1 cream, 1 sugar) or tea (2 sugars, yes, I remember!) and a stroopwafel, but you use your powers to eat it, floating it in front of your mouth and biting into it while you re-read what you’ve written. You’re fascinating to observe, sir, captivating to witness._

_I can’t help my feelings. I’ve tried ignoring them, I’ve tried seeking out other romantic partners, I’ve tried so many things, sir, but nothing has worked. I’m in love with you, absolutely in love with you, and I can’t help but want to be with you._ ”-

Siebren sat down in his seat, his heart pounding in his ears. He continued to read:

-“ _But, sir, I’m not oblivious to the taboo that our hypothetical relationship would be. I know that I am 40 years your junior; I know that I’m merely a glorified coffee girl and errand runner while you are a genius scientist who has been kissed by the universe; someone who can bend the force of gravity to his every whim and will. I know what a risk I am taking, not just personally, but professionally, in confessing my feelings to you. ~~M/r\d/e/K\u/i\per~~ Siebren, you have always told me that honesty is important in life, and while I know you meant that in the context of not exaggerating statistics or fudging results, I can’t help but apply it to my life in general. I’m in love with you, and I feel so much so that I need to tell you._”-

A bead of sweat trickled down Siebren’s brow as he pressed his trembling lips against his mug, taking a sip. His heated, moist palms held the cup’s handle tightly, his entire arm shaking from anticipation and shock.

-“ _Sir, I have reason to believe that Ms. O'Deorain has caught on to my feelings for you. I worry that she might fire me, replace me, or stage an “accident” for me. She won’t hesitate to get rid of me if she thinks that I’m hindering your work. Because of this, I’ve been considering leaving willingly, as to save my own life.  
_

 _I’m also fairly certain that you don’t reciprocate these romantic feelings, which I’m not upset about! Rather, I don’t fault you for not feeling the same way. I completely understand that a man of your caliber (and age) would want to be with someone more appropriate. This letter is not meant to guilt you into loving me. It’s simply a confession of my feelings, and an explanation of why I might soon disappear, be it by my own choice or factors beyond my control._ ”-

Siebren’s heart sank upon reading that Celeste could be leaving him. His brow furled at the thought of Moira getting rid of her, and he gritted his teeth in rage at the thought of anyone hurting such a sweet girl. As a bitter breath left his scowling face, he came to a stark realization: _he returned her feelings_. His rage quickly turned into shame, then fear, then bliss, and finally, awe. He kept reading, with bated breath.

-“ _I’m sorry that I couldn’t confess these feelings to you sooner, sir. If you’d like, you can trash this letter and we can forget about this whole ordeal. I can try harder to overcome my romantic feelings for you. Surely there must be something that can be done to rid myself of them. I want to be a part of your life, sir, be it as a coffee girl, an apprentice, a friend, a lover, even a test subject…. My life would be so dark and empty without you in it, sir._

_I don’t know what will happen after I leave you this letter. I don’t know if Ms O’Deorain will find it first, I don’t know if you even will. All I know is that I can’t hide these feelings anymore. Forgive me, please._

##  _~ Celeste_ ”

Siebren gently laid the letter on his desk, resting his head on his intertwined fingers. He closed his eyes, sighing deeply. He was confused, afraid, worried… and elated. His heart was racing, his stomach filled with butterflies; his whole body awash with a warmth he hadn’t felt in so long. He sat there for what seemed like hours, his thoughts consumed with questions and possible outcomes; debating his heart, analyzing his feelings. The items in the room around him lost their tether to the floor and floated up skyward, until finally, he opened his eyes. He was certain of what he had to do. The furniture slowly drifted back down to the ground as he reached for the communicator on his desk. Taking it in one hand, he dialed Celeste’s number.

The calling tone filled the empty room, echoing off of the walls. “Hello..?” said a soft voice from the other end.

“Ms. Aucosmus?” said Siebren, taking the letter in his free hand and glancing over it again. “It’s de Kuiper. I’m in dire need of your assistance in my lab.”

“Right now?! Sir… with all due respect, it’s nearly 3 in the morning.”

Siebren chuckled gently. “Science… discovery… these things don’t care about something as trivial as time, Celeste.”

Celeste let out an exasperated sigh, followed by a yawn. “If you insist, sir. I’ll be there in ten.”

“Thank you. It’s most appreciated, I assure you.” Siebren ended the call and set the communicator back down on the desk, a smirk on his face.

Celeste hastily walked down the hall to Siebren’s lab, struggling to get her bed head into a hair tie. She adjusted her glasses, fidgeting with her bag’s strap as it slipped off of her shoulder. She took out her keycard and held it up to the scanner, which beeped in approval and flashed a green light. Taking a deep breath, she opened the lab door and stepped into the pitch-black room. “Mr. de Kuiper..?” she said, as the lab door shut behind her. She slid her hand against the cold wall in an effort to find the light switch, but her fingers met something round and hard where the switch should have been. “What… is that..?” she said, digging around in her bag to find her mini light. She pushed aside pens and paperclips until her hand wrapped around the tiny flashlight. Quickly, she pulled it out and turned it on, shining the beam of light in the direction of the light switch.

The light revealed a familiar lab coat on a familiar torso, attached to a familiar pair of legs floating inches above the ground. “Sir..?” she said, a worried tone in her voice. “Why are you covering the light switch..?” Siebren said nothing, instead raising his other hand and snatching the flashlight out of Celeste’s hands, turning it off and putting it into his coat pocket. 

“W-why did you do that..?!” squealed Celeste, baffled and taken aback at Siebren’s sharp and sudden movements. “Did you start a new, light-sensitive project, sir..?” Siebren, again, kept silent, hovering in place. The very little light seeping into the room through the windows cast a shine into Siebren’s ice blue eyes, which seemingly didn’t blink while he stared at Celeste.

The two stood in silence for a short while longer, before Siebren’s low voice broke the quiet. “I found your letter, Ms. Aucosmus.” he crooned softly, his floating form looming over her. “It was most interesting.”

Celeste pressed her back against the lab door, fearfully. “…you aren’t going to kill me, are you..? I promise, I can leave, I won’t ever come back, I won’t ever get in your way again…”

“Kill you?! Goodness, no!” Siebren flicked on the lights, never taking his eyes off of her. “Why would I hurt the person that I love?”

Celeste squinted in the sudden brightness of the room, but upon hearing Siebren’s words, her eyes lit up in joy. “…p-person that you… you…!” Celeste’s lips curled into a smile.

Siebren hovered over to her and lowered himself closer to the ground. He realized that even if he were to rest his feet on the floor, he still towered over her. “Brace yourself, please.” he said calmly, lifting his hands. Celeste began to float upwards as Siebren brought her lips closer to his. A warm smile spread across his face as he caressed her calescent cheek with his chilly fingers. “Celeste, your letter touched me. All things considered, I would like to try being in a relationship with you. It’s far too interesting a proposal to pass up.”

Celeste’s cheeks turned a soft, rosy color. “I would love that more than anything, sir!”

Siebren chuckled. “Please, my dear, call me Siebren.” He carefully raised her chin with his fingers, pressing his lips to hers in a passionate kiss. Celeste’s bag slipped off of her arm and hit the floor, pens scattering everywhere. But that didn’t matter. Nothing else mattered in that moment, not science, not the universe, not Ms. O’Deorain or Talon… Nothing in all existence mattered to Siebren in that moment but Celeste, nothing mattered to him but _them_.

**Author's Note:**

> The title is based on Ruelle's "War of Hearts". I found it via an MEP video.  
> This was my first self-insert x canon fanfic. I wrote it back in 2019 and posted it to my self-ship tumblr. I think only one other person read it, but I don't really care. It's one of my favorite fics I've ever written!  
> While I say this is a one-off, it's technically a part of an overarching series, but I haven't written any other stories yet.  
> I'm new to the site and tagging things properly was a bit of a challenge, so please let me know if I did something wrong.


End file.
